Finish eliminating PlatformWindowMus

ui/views/mus/window_tree_host_mus.h

Index: ui/views/mus/window_tree_host_mus.h
diff --git a/ui/views/mus/window_tree_host_mus.h b/ui/views/mus/window_tree_host_mus.h
index 30da7ed2d3fb0b6b0d99855d1ba1fb6128d281c9..e1930c341e9b304a932ce3a4bba173dee97b672c 100644
--- a/ui/views/mus/window_tree_host_mus.h
+++ b/ui/views/mus/window_tree_host_mus.h
@@ -11,6 +11,10 @@
 
 class SkBitmap;
 
+namespace bitmap_uploader {
+ class BitmapUploader;
+}
+
 namespace mus {
 class Window;
 }
@@ -19,6 +23,10 @@ namespace shell {
 class Connector;
 }
 
+namespace ui {
+class ViewProp;
+}
+
 namespace views {
 
 class InputMethodMUS;
@@ -32,8 +40,6 @@ class VIEWS_MUS_EXPORT WindowTreeHostMus : public aura::WindowTreeHostPlatform {
                     mus::Window* window);
   ~WindowTreeHostMus() override;
 
-  PlatformWindowMus* platform_window();
-
  private:
   // aura::WindowTreeHostPlatform:
   void DispatchEvent(ui::Event* event) override;
@@ -44,6 +50,10 @@ class VIEWS_MUS_EXPORT WindowTreeHostMus : public aura::WindowTreeHostPlatform {
   NativeWidgetMus* native_widget_;
   std::unique_ptr<InputMethodMUS> input_method_;
 
+  // Bitmap management.
+  std::unique_ptr<bitmap_uploader::BitmapUploader> bitmap_uploader_;
+  std::unique_ptr<ui::ViewProp> prop_;
+
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostMus);
 };